Radio and phonographic amplifying resonator



Oct. 20, 1925.

W. C. LARSON ET AL.

RADIO AND PHONOGRAPHIC AMPLIFYING RESONATOR Filed April 26, 1923 2 Sheets-Sheet .1

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Oct. 20, 1925- W. C. LARSON ET AL RADIO A'ND PHONOGRAPHIC AIPLIFYING Rasomu'oli Filed April 26, 1925 2 Sheets-Shaw 2 gnue'nfoz l1, (154/1904 44/ Patented Oct. 20, 1925.

UNITED STATES WILLIAM C. LARSON AND CHARLES P. WEGNIJR. O l? RADIO AND PHONOGRAPHIC ltMPL'ITYlI .3.

Application filed Apr i1 26, 1923.

To all whom it may concern:

Be it known that we, WILLIAM C. LARSON and CHARLES P. VVEGNER, citizens of the United States, residing at Two Harbors, in the county of Lake and State of Minnesota, have invented certain new and useful Improvements in Radio and Phonographic Amplifying Resonators, of which the following is a specification.

This invention relates to radio speakers and phonographs, and the primary object of the invention is to provide an improved horn or sound amplifying compartment, so constructed as to first, preserve the delicate overtones or partials and to prevent the damping or smothering thereof by the harsher fundamentals or full notes; second, to reflect back the sound waves into the sound chamber giving additional volume to the overtones; third, the breaking in of prolonged or pronounced reverberations, which often cause, in vocal selections particularly, blurred or jumbled words; fourth, the return of filtered vibrations resulting in the damping of short sound waves which are one of the principal causes of friction noises; fifth, the creation of a perfect balance in the functioning power of the various parts or segments of the horn resultin in the elimination of discordant vibrations, and sixth, the giving of a sound of great volume, clear and mellow, resulting from the overlapping columns of sound waves passing to and fro in the horn.

Another prime object of the invention is to provide an improved horn or sound amplifying compartment surrounded by closed air chambers or compartments, the closed air compartments or chambers functioning to insure the proper balance of tone, and to preserve the delicate overtones that would otherwise be damped out.

A further object of the invention is to provide a horn orsound amplifying compartment having each wall or segment thereof provided with a closed air chamber or compartment, which prevents the leakage of the sound waves from the tone or amplify ing compartment or chamber.

A still further object of the invention is to provide an improved sound amplifv'i. chamber or horn of the above character, which will be durable and efficient in use, one that will be simple and easy to manufacture, and one which can be incorporated '0 FLLZRBOES. T IINN'ESOTA.

RlSC Nr-lrTOR.

Serial No. 634,816.

with the ordinary types of phonographs and radio speakers.

l'ith these and other objects in view the invention 0 ists in the novel construction, arrangeme (L formation oi parts. as wil he hereinafter more specifically claimed and illustrated in the accompanying drawings, forming a part of this specification in which drawings:

Figure l is a plan view of the improved horn or sound ni iliiwing member, the throat thereof be shown in section.

Figure 2 a transverse section through the sound aniplitiving horn taken on the line 9-2 of l igurc 1 looking in the direction of the arrows.

Figure 3 is a similar section taken on the line 3-3 of Figure 1 looking in the direction of the arrows.

Figure 4 is a longitudinal section through the improved horn tal-ceu on the line 4-l of Figure 1.

Referring to the drmvings in detail, wherein similar reference characters designate corresponding parts throughout the several views. the letter A generally indicates the improved phonograph and radio sound amplifying ho n. The sound amplifying horn includes the main body por tion 5 constituting the tone chamber and the upwardly extending :urcuately curved d ascribed,

throat section 6, which is adapted to be connected in the ordinary manner with the tone arm of the phonograph (not shown) and base of a loud speaker.

The tone chamber 5 and the throat 6 are double walled and these walls form a con tinuation of one another so as to form a continuous and uniformlr diverging sound con duit extending from the tone arm to the outer end of the tone compartment. The innor wall 7 of the tone chamber 5 and the outer wall 8 thereof each includes four flat jointed side pieces formed of thin sounding board n'iaterial, preferably of wood of the qualitv and dimensions employed in violin or zither structures and which are numbered 9 and 10 respectively in the drawings. The side pieces 9 of the inner wall 7 have the upright portions thereof extended to the outer wall 8. as indicated by the reference character 10. thus defining independent chambers 12 and 13 at the sides of the horn and independent chambers 14 and 15 at the top and bottom of the born.

g r V As stated, th walls of the throat 6 form a continuation of the walls of the tone compartment 5 and thus it can be seen that the inner converging ends of the inner and outer walls 7 and 8 of the tone compartment 5 are curved upwardly and inwardly as at 16 and 17. Connecting ieces 18 are employed at the front end 0 the horn to unite the walls 7 and 8 together and similar pieces 19 are utilized to connect the walls together at the outer end of the throat 6.

O enings 20 can be made in the extended portions 10 of the upright portion of the inner walls 9 at equidistantly spaced points. so as to unite thechambers 12, 13, 14 and 13 to ether.

rom the foregoing it can be seen that each wall or segment of the amplifying horn is provided with a chamber and thus all sides of the horn are treated in a like manner, which insures the proper balance of tone and tends to preserve the delicate overtones that would otherwise be lost. It is of course essential that all sides of the horn be treated the same, as vibrations or sound waves passing from the reproducer of the phonograph and through the tone arm are expanded into the resonance chamber evenly on all surfaces thereof.

It has been found that a horn constructed in the above manner will preserve the peculiar tone or timbre of each individual instrument, such as the flute, violin, and the like. The chambers 12, 13, 14 and 15 act as members corresponding to the overtones developed in different instruments and will vibrate sympathetically and harmonicall one with the other. In this manner discord ant vibrations are to a great extent avoided, and the sound. produced will be of a pure andricher quality.

The horn will efiectively prevent the filtering of vibrations through the resonator walls and thus revent loss in the volume of the sound in t tone chamber.

All of the side walls 7 of the improved amplifier are fiovided with harp-shaped? openings 25. ese openings play an 1111?, portant role in the horn, in that they im- N prove the tonal qualities by producingiibersfw of varying lengths whichwould a T breaking up of prolonged reverberations-ffi 'f and to improve the resonator from an unistic standpoint.

Changes in details may be made withoiit departing from the spirit or the scope it I E as; I I 5 this mve'ntiont Wlgat we (tlzlaim it; new if: i

1. i seen amp i ing orn com ris ng tone chamber and th roat having a eontim one sound conduit therethrough and :imcliz ing inner and outer spaced walls, end pieces connecting the walls together at the 001292}, terminals of the throat and tone chambon,, certain of the inner walls being extended to, engage the inner surface oi the outerto form independent compartments, said tended portions of the inner walls being pro, vided with openings to establish commum catior kbetwean all of f;he cohxgpartments.

2. soun ampli ing rn; com riei a tone chamber and a threat having a m tin'uous sound conduit thenethroughmnd in cluding inner and outer s walls,.t outer wall being formed of nnperforatemm II terial, imperforate end pieces eonnectin walls together at the outer terminals 'thetj throat and tone chamber, certain of sha ia, ner walls being extended to engage the ilmm-- surface of the outer wall to form indepeadi. M ent compartments, said extended portioning the inner walls being proeiyd djwith "M ings to establish communication between of the compartments, the inner-walls at: tone chamber being provided with 7 p p s 7 .5:

In testimony whe eofi me afiix our tures. WILLIAM e.- LARSQH)? GHARLES P.

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